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When to Plant Tomatoes in Hanson County, SD

Hanson County, South Dakota Zone 5a May

Your May planting checklist for Hanson County, South Dakota

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Hanson County, South Dakota.

Avg. last frost May 6
Avg. first frost October 5
Soil temp (4") 56°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
  1. Time to transplant tomatoes

    Frost risk is low now in Hanson County, South Dakota. If you've been covering beds overnight, you can stop.

  2. Outdoor sowing time: tomatoes

    Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.

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Tomatoes are the most popular home garden crop, available in thousands of varieties from tiny cherries to massive beefsteaks. They are warm-season plants needing full sun.

Hanson County, South Dakota is in USDA Zone 5a. The average last spring frost is May 6 and the first fall frost is October 5, giving you a growing season of approximately 152 days.

At an elevation of 614 feet, Hanson County receives approximately 28.4 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Tomatoes to ensure they mature before fall.

Hanson County, SD (Zone 5a) Moderate season
152 days
Last Spring Frost May 6
152 growing days
First Fall Frost October 5

Hanson County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (9 days to spare)
Start indoors: Mar 2 Transplant: May 11 🍅 Harvest: Jul 13 – Sep 21
Recommended (50%) ✓ Fits season (5 days to spare)
Start indoors: Mar 11 Transplant: May 20 🍅 Harvest: Jul 22 – Sep 30
Safe Start (90%) ✓ Fits season (5 days to spare)
Start indoors: Mar 21 Transplant: May 30 🍅 Harvest: Aug 1 – Oct 10

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Hanson County

How your county's soil matches Tomatoes's growing requirements.

Soil pH

Your soil pH (6.4–7.4) overlaps with Tomatoes's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in Hanson County is excellent for Tomatoes — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.6%). Annual compost additions will help Tomatoes.

How to Plant Tomatoes

0.5"
Planting Depth
24"
Between Plants
36"
Between Rows

Succession Planting Tomatoes

2
successive plantings in your 152-day season

Sow every 6.9 weeks. Last sowing by Jul 12 to harvest before frost.

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
0.8″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 562 gal / 100 sq ft

Monthly Watering Guide for Tomatoes

Tomatoes needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.

Month Tomatoes Needs Rainfall You Supplement Action
Jan 0.7" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 3.3" 0" ❄️ Dormant
May 5.2" 4.7" 0.5" 💧 Light watering
Jun 5.2" 4.1" 1.1" 💧 Light watering
Jul 5.2" 3.5" 1.7" 💧 Light watering
Aug 5.2" 3.4" 1.8" 💧 Light watering
Sep 5.2" 2.7" 2.5" 💧 Light watering
Oct 5.2" 1.7" 3.5" 🚿 Regular watering
Nov 1.1" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Hanson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Tomatoes Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Tomatoes needs ~888 GDD — county provides 1,862 GDD Excellent fit

Tomatoes Planting Timeline — Hanson County, SD

Tomatoes Planting Calendar

Activity When Date Range
Start Indoors March 11 Mar 11 – Mar 25
Transplant Outdoors May 20 May 20 – Jun 3
Direct Sow May 13 May 13 – Jun 3
Harvest July 22 Jul 22 – Sep 30

Plant 0.5" deep · 24" apart · Rows 36" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July Harvest
August Harvest
September Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.2"/week · 1-2 times/week

📅 Days to Maturity

60–85 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

152 days in Hanson County

Growing Tips for Tomatoes in Hanson County

Direct sow Tomatoes outdoors after May 06 in Hanson County when soil has warmed and frost danger has passed.

Common pests for Tomatoes in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 6-8 weeks before last frost. Bury transplants deep to encourage rooting along the stem. Provide consistent moisture to prevent blossom end rot and cracking.

Companion Planting

Good Companions

Avoid Planting Near

  • Cabbage
  • Fennel
  • Potatoes

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Tomatoes Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Scoop seeds from ripe fruit; ferment 2-3 days to remove gel coating.
Storage Store airtight; viable 4-6 years at 35°F, under 45% humidity.

Isolate 25 ft between varieties for purity. Use open-pollinated varieties for true-to-type seeds.

Frequently Asked Questions

When should I plant Tomatoes in Hanson County, SD?

Hanson County is in Zone 5a with an average last frost of May 6. Plan your Tomatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hanson County, SD?

Hanson County, South Dakota is in USDA Hardiness Zone 5a. The average last spring frost is May 6 and first fall frost is October 5.

🌱

Your Hanson County Garden Planner — Free

A 24-page printable planner built for Hanson County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Hanson County, SD. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.